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Estrogen , Oestrogen; Types, Uses, Contra Indications, Side Effects, Interactions

Estrogen, oestrogen, is the primary female sex hormone. It is responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens in females that have estrogenic hormonal activity: estrone, estradiol, and estriol. The estrane steroid estradiol is the most potent and prevalent of these.

Estrogens are a pharmaceutical preparation containing a mixture of water-soluble, conjugated estrogens derived wholly or in part from URINE of pregnant mares or synthetically from ESTRONE and EQUILIN. It contains a sodium-salt mixture of estrone sulfate (52-62%) and equilin sulfate (22-30%) with a total of the two between 80-88%. Other concomitant conjugates include 17-alpha-dihydroequilin, 17-alpha-estradiol, and 17-beta-dihydroequilin. The potency of the preparation is expressed in terms of an equivalent quantity of sodium estrone sulfate.

Types of Estrogen

Estrogens agonists

Steroidal: Alfatradiol
Certain androgens/anabolic steroids (e.g., testosterone, testosterone esters, methyltestosterone, metandienone, nandrolone esters) (via estrogenic metabolites)
Certain progestins (e.g., norethisterone, noretynodrel, etynodiol diacetate, tibolone)
Clomestrone
Cloxestradiol acetate
Conjugated estrogens (+medroxyprogesterone acetate, +bazedoxifene)
Epiestriol
Epimestrol
Esterified estrogens (+methyltestosterone)
Estetrol^†
Estradiol
Estradiol esters (e.g., estradiol acetate, estradiol benzoate, estradiol cypionate, estradiol enanthate, estradiol undecylate, estradiol valerate, polyestradiol phosphate)
Estramustine phosphate
Estriol
- Emmenin
- ProgynonEstriol esters
Estrone
- Estrone sulfate
- Estropipate (piperazine estrone sulfate)
- Estrone esters
Ethinylestradiol
- Ethinylestradiol sulfonate
Hydroxyestrone diacetate
Mestranol
Methylestradiol
Moxestrol
Nilestriol
Prasterone (dehydroepiandrosterone; DHEA)
- Prasterone enanthate
- Prasterone sulfate
Promestriene
Quinestradol
Quinestrol

Nonsteroidal: Benzestrol
Bifluranol
Chlorotrianisene
- Dienestrol diacetateDienestrol
Diethylstilbestrol (stilbestrol)
Diethylstilbestrol esters/ethers
- Dimestrol (diethylstilbestrol dimethyl ether)
- Fosfestrol (diethylstilbestrol diphosphate)
- Mestilbol (diethylstilbestrol monomethyl ether)
Doisynoestrol (fenocycline)
Hexestrol
- Hexestrol esters
Methallenestril
Methestrol dipropionate (promethestrol dipropionate)
Paroxypropione
Quadrosilan
Triphenylbromoethylene
Triphenylchloroethylene
Zeranol

Overview of actions

Structural

Mediate formation of female secondary sex characteristics
Accelerate metabolism
Increase fat store
Stimulate endometrial growth
Increase uterine growth
Increase vaginal lubrication
Thicken the vaginal wall
Maintenance of vessel and skin
Reduce bone resorption, increase bone formation

Protein synthesis
- Increase hepatic production of binding proteins
Coagulation
- Increase circulating level of factors plasminogen
- Decrease antithrombin III
- Increase platelet adhesiveness
Lipid
- Increase HDL, triglyceride
- Decrease LDL, fat deposition
Fluid balance
- Salt (sodium) and water retention
- Increase cortisol, SHBG
Gastrointestinal tract
- Reduce bowel motility
- Increase cholesterol in bile
Melanin
- Increase pheomelanin, reduce eumelanin
Cancer
- Support hormone-sensitive breast cancers (see section below)
Lung function
- Promotes lung function by supporting alveoli (in rodents but probably in humans).
Uterus lining
- Estrogen together with progesterone promotes and maintains the uterus lining in preparation for implantation of fertilized egg and maintenance of uterus function during the gestation period, also upregulates oxytocin receptor in myometrium
Ovulation
- The surge in estrogen level induces the release of luteinizing hormone, which then triggers ovulation by releasing the egg from the Graafian follicle in the ovary.
Sexual behavior
- Promotes sexual receptivity in estrus, and induces lordosis behavior.In non-human mammals, it also induces estrus (in heat) prior to ovulation, which also induces lordosis behavior. Female non-human mammals are not sexually receptive without the estrogen surge, i.e., they have no mating desire when not in estrus.
- Regulates the stereotypical sexual receptivity behavior; this lordosis behavior is estrogen-dependent, which is regulated by the ventromedial nucleus of the hypothalamus.
- Sex drive is dependent on androgen levels only in the presence of estrogen, but without estrogen, free testosterone level actually decreases sexual desire (instead of increases sex drive), as demonstrated for those women who have hypoactive sexual desire disorder, and the sexual desire in these women can be restored by administration of estrogen (using oral contraceptive). In non-human mammals, mating desire is triggered by estrogen surge in estrus.